This invention relates to an improved tube coupling for connecting the two tube lengths which coupling provides a locking engagement, an effective liquid seal when the tube lengths are connected and a quick disconnect capability. More particularly, the invention relates to tube couplings for medical use although it is not limited to medical applications.
In the prior art many tube couplings are shown comprising a male body and a female body and which provide for a positive locking capability when joining the male and female bodies together. For example, see fingers 34, latch blades 36 and groove 38 in U.S. Pat. No. 3,245,703; see arms 32 and 34 with latch projection 36 and annular shoulder 30 in U.S. Pat. No. 3,394,954; see molded plastic latch 154 in FIG. 2 of U.S. Pat. No. 3,602,009; see the coupling element of FIG. 5 and the rear edge of collar 15 in U.S. Pat. No. 3,603,621; see the inwardly projecting flanges 18 and recessed collar member 21 in U.S. Pat. No. 4,123,091; and the intermediate ring 100 and rim 58 of published UK Patent Application No. GB 2,092,690 A. The various locking mechanisms described in the above-mentioned patent applications are released so that the couplings can be disconnected by either applying a squeezing type pressure to a portion of the latch or locking mechanism (U.S. Pat. Nos. 3,245,703; 3,394,954; 3,602,009; and the UK Patent Application), or by turning, twisting or rotating various portions of the couplers relative to one another (U.S. Pat. Nos. 3,603,621 and 4,123,091).
To provide a liquid seal various approaches are used in the prior art, but one of the most common comprises placement of separately manufactured O-rings in annular grooves surrounding a portion of the male body which portion is inserted in a corresponding cavity of the female body. In particular, see the pair of O-rings 13 and 28 in U.S. Pat. Nos. 4,123,091 and 3,394,954, respectively. O-rings generally function by having a larger outer diameter when placed in the grooves on the male member than the outer diameter of the corresponding portion of the male member. The O-rings are made of a compressible material such as rubber and when inserted in the female cavity, they are compressed against the relatively smooth interior surface thereof to form a liquid seal.
As described above the various prior art devices require separate approaches for providing a locking mechanism and a liquid seal. Further, the prior art devices require some form of separate action to remove the locking action of the locking device; and require the inclusion of separately manufactured O-rings in the assembly of the tube coupling.